The structures of two series of sesquiterpene lactones (the ‘α’-series 11, 12 and 16 and the ‘β’-series 15, 17 and 18) present in the herb feverfew have been revised in the light of both X-ray analysis and chemical correlations. A biosynthetic pathway is proposed, involving a Diels–Alder type addition of oxygen followed by two contrasting rearrangements, starting from a common intermediate, the cyclopentadiene 19, which has not been identified in feverfew extracts but which is related to a recently isolated structure. The activity of some of these metabolites as well as of the major sesquiterpene lactone present in feverfew, parthenolide 2, and some simple synthetic models as inhibitors of human blood platelet function has been determined. The possible relevance of this effect to migraine prophylaxis by feverfew is briefly discussed.
根据 X 射线分析和
化学相关性,对发热草中的两个
倍半萜内酯系列("α "系列 11、12 和 16 以及 "β "系列 15、17 和 18)的结构进行了修订。提出了一种
生物合成途径,其中包括一个 Diels-Alder 型
氧气加成过程,然后是两个截然不同的重排,从一个共同的中间体
环戊二烯 19 开始,该中间体尚未在发热草
提取物中发现,但与最近分离出的一个结构有关。我们已经确定了其中一些代谢物以及发热草中的主要
倍半萜内酯 Parthenolide 2 和一些简单合成模型作为人体血小板功能
抑制剂的活性。本文简要讨论了这种作用与发热草预防偏头痛的可能相关性。